"FBA Rouen Production" uses $200$ disk break per month, each unit costs $$100.$ These disks are purchased from supplier AB that is $90$ km away from FBA. The production manager estimates that the annual unit holding cost is $15\%$ of the unit cost and the unit ordering cost is $$25.$ Currently, the inventory policy is placing two orders per month along the year to satisfy the annual demand. Calculate: $($Leave your answers with $2$ decimals and use $(.)$ as decimal separator.

a$)$ Economic order quantity $($EOQ$)=$ R$$ponse

$(1$pt$)$

b$)$ Number of orders if the manager orders by EOQ $=$ R$$ponse

$(1$pt$)$

c$)$ How much the company can save per year in stock management cost $($do not consider the material cost$)$ if it uses the EOQ? $-->$ Saving $=$ R$$ponse

$(2$pts$)$

d$)$ Suppose that the mothly demands is multiplied by four. The EOQ will be multiplied by what factor? Factor $=$ R$$ponse

$(1$pt$)$